What arrangement will you make about payment ?   We shall open an irrevocable L / C to cover our shipment from Shanghai to Hamburg . Is it at sight or after sight ?   At sight of course .   Some customers demand that 80 % of the credit amount be paid at sight , and the rest be paid after the machines are proved satisfactory on trial .   I am afraid that can't be done . We have never done business on such terms .   But such terms are quite common in the machinery trade . Other suppliers are offering better terms . Some even allow payment 60days after sight .   We ask for full payment at sight , because we guarantee 90 % mechanical efficiency for all our products . You don't have the same guarantee from other suppliers . The usual percentage is around 85 .   That's true . I'm eager to know if you could send some fitters to ensure good operation .   Yes . We usually send technicians abroad to offer after-sales service to our customers .   If you send fitters along with the machines to ensure that all the machines run properly , and if you provide after-sales service , we agree to make the payment in full .   Thank you . I am glad we have come to an agreement at last . 